Large ileal lipomas over 2 cm can cause symptoms, that may require a resection. Due to the narrow lumen and thin walls of the ileum, endoscopic treatments can have a high risk of adverse events and require technical expertise, thus surgical resection is currently the mainstay of treatment. To overcome the technical challenges, we developed a novel method to endoscopically resect terminal ileal lipomas. The technique involves extracting the lesion into the cecum, which creates sufficient space to maneuver, and a better field of view. The lipoma is resected with endoscopic mucosal resection or endoscopic submucosal dissection. The appearance of the lipoma protruding out of the ileocecal valve resembles that of a tongue sticking out of the mouth, thus we named this the "tongue out technique". To assess the technical feasibility of this method, we retrospectively analyzed seven cases of terminal ileal lipoma that were endoscopically resected using the "tongue out technique" at NTT Medical Center Tokyo between January 2017 and October 2023. Technical success was 100% and en bloc resection was achieved in all cases. The median size was 31 (14-55) mm. Three cases were resected with endoscopic mucosal resection while endoscopic submucosal dissection was performed on the other four cases. There was one case of delayed post-endoscopic mucosal resection bleeding, which was caused by clip dislodgement. There were no perforations. No recurrence of the lipoma or associated symptoms have been observed. This new technique can allow more ileal lipomas to be treated with minimally invasive and organ-preserving endoscopic procedures.
Video 1Clip with line-pulley securing technique with plastic detachable snare for endoscopic submucosal dissection defect closure.
BACKGROUND: There is a lack of reports on the use of direct oral anticoagulants (DOACs) during colorectal endoscopic submucosal dissection (ESD). AIMS: We aimed to assess whether the use of DOACs is associated with a higher incidence of delayed bleeding (DB) after ESD. METHODS: A total of 4175 colorectal neoplasms in 3515 patients were dissected at our hospitals during study period. We included 3909 lesions in the final analysis. The lesions were divided into two groups: the no-AT group (3668 neoplasms) and the DOAC group (241 neoplasms). We also compared the DOAC withdrawal group (154 neoplasms) and the DOAC continuation group (87 neoplasms). RESULTS: Among the 3909 lesions, DB occurred in a total of 90 cases (2.3%). The rate of DB was 2.2% (82/3668), and 3.3% (8/241), respectively. There were no significant differences in the rate of DB between the no-AT group and the DOAC group. In the DOAC group, there were no significant differences in the rate of DB between the withdrawal group (5.2%, 8/154) and the continuation group (0%, 0/87). The multivariable analysis identified the location of the lesion in the rectum (odds ratio [OR], 4.04; 95% confidence interval [CI], 2.614-6.242; p < 0.001) and lesions ≥ 30 mm in diameter (OR, 4.14; 95% CI, 2.349-7.34; p < 0.001) as independent risk factors for DB. CONCLUSIONS: Our findings suggest that DOAC use has no significant important on the rate of DB. Prospective studies are warranted to determine whether treatment with DOACs should be interrupted prior to colorectal ESD.
Colorectal Neoplasms , Endoscopic Mucosal Resection , Humans , Endoscopic Mucosal Resection/adverse effects , Postoperative Hemorrhage/chemically induced , Postoperative Hemorrhage/epidemiology , Retrospective Studies , Risk Factors , Colorectal Neoplasms/complications , Anticoagulants/adverse effects
A 57-year-old woman with no significant medical history was referred after a colonoscopy for abdominal distension, which revealed a tumor in the lower rectum. Pre-operative colonoscopy showed the tumor was 12 mm in size, located from the anorectal junction to beyond the dentate line, and was diagnosed as high-grade intramucosal neoplasia or shallow submucosal invasive cancer. Endoscopic submucosal dissection was performed, and the lesion was resected en bloc. Pathological examination revealed moderately differentiated tubular adenocarcinoma with tubulovillous adenoma. The stratified squamous epithelium adjacent to the anal side of the lesion showed pagetoid spread of atypical cells with positive horizontal margins. We referred her to a surgeon for radical treatment. The mucosa surrounding the endoscopic submucosal dissection scar was normal on narrow-band imaging magnification. We marked its oral side endoscopically as the resected boundary. Transanal local excision was performed. The horizontal margins were positive because atypical cells had spread into the stratified squamous epithelium of the anorectal side of the lesion. The patient was followed on an outpatient basis. Sixty days postoperatively, residual tumor growth was observed. The second local resection was performed after mapping biopsy. All resection margins were negative, there was no lymphovascular invasion. One year after surgery, no recurrence was observed. Regarding endoscopic findings, there are no reports of endoscopic findings of the rectal mucosa, or the squamous epithelium of the anus of pagetoid spread. Here, we report a review of perianal Paget's Disease that resulted in difficulties in borderline diagnosis of pagetoid spread, resulting in multiple therapeutic interventions.
Objectives: Previous studies of cold snare polypectomy (CSP) for sessile serrated lesions (SSLs) ≥10 mm were performed by experienced endoscopists, and therefore their skills might have significantly influenced results. In this study, we compared the efficacy and safety of CSP for SSLs ≥10 mm between experienced and trainee endoscopists. Methods: In a 1:1 propensity score matched retrospective cohort study, we compared the complete resection rate, en-bloc resection rate, adverse event rate, and procedure time between experienced and trainee groups. Thirteen endoscopists performed CSP, and we defined the experienced group as endoscopists with board certification from the Japan Gastroenterological Endoscopy Society. Results: We examined 616 lesions with SSLs ≥10 mm resected by CSP between February 2018 and May 2022. We excluded 61 lesions from the analysis because they had simultaneously undergone hot snare polypectomy (n = 57) or had been taken over by experienced endoscopists from trainees in the CSP procedure (n = 4). Finally, we identified 217 propensity score-matched pairs (n = 434). Between experienced and trainee groups, the results were complete resection rate (100 vs. 100%; p = 1.00), en-bloc resection rate (73.2 vs. 75.6%; p = 0.24), adverse event rate (3.2 vs. 2.8%; p = 0.77), or procedure time (6.2 vs. 5.9 min; p = 0.64). Conclusions: We have demonstrated the safety and efficacy of CSP for SSLs ≥10 mm performed by experienced and trainee endoscopists.
A 51-year-old woman visited our hospital with the chief complaint of tarry stools. Contrast-enhanced abdominal computed tomography revealed leakage of contrast medium into the lumen of the small intestine. Subsequently, a double-balloon endoscopy was performed, which revealed a submucosal mass-like lesion in the jejunum. Although hemostasis was attempted with clips, complete hemostasis was difficult to achieve, and angiographic embolization was performed. Nevertheless, the anemia progressed, and a small bowel resection was performed. Histopathological examination led to a diagnosis of a ruptured submucosal aneurysm of the small intestine. Endoscopic hemostasis is often difficult to achieve for submucosal aneurysms in the intestine. The submucosal tumor-like finding observed on endoscopy in submucosal aneurysms is termed an "SMT-like sign" and is considered an important finding to diagnose aneurysms.
A 25-year-old man was referred to our center for investigation of a gastric submucosal tumor and an ulcer that had developed on its oral side. Endoscopic ultrasonography findings suggested the presence of an ectopic pancreas, and treatment with an oral proton pump inhibitor was planned for the ulcer. Over the subsequent 3 years, the patient endured recurring epigastric pain and episodes of passing black stools. Emergency endoscopy revealed that the morphology of the gastric submucosal tumor had transformed into a pedunculated polyp-like morphology with a bleeding ulcer at the apex of the lesion. Endoscopic hemostasis using hemostatic forceps was performed. However, the patient continued to pass black stools. In light of the persistent symptoms and unique morphology of the lesion, endoscopic resection was attempted as a curative approach. The lesion was excised by hot snare polypectomy. Post-treatment, the patient exhibited no signs of recurrence, marking a successful resolution. Three months later, a gastroduodenal endoscopy showed that the excised site had undergone scar formation without recurrence of the lesion. This case holds significant clinical value as it demonstrates the efficacy of a minimally invasive treatment strategy in managing repeated bleeding ulcerations of an ectopic pancreas, ultimately achieving a complete cure.
OBJECTIVES: The resection of vertical margin-negative submucosally invasive colorectal cancer (CRC) relies on the pathological risk assessment of lymph node metastasis. However, no large-scale study has clarified the endoscopic resection (ER) outcome for submucosally invasive CRC, focusing on the vertical margin status. This retrospective study aimed to examine vertical margin involvement in ER for submucosally invasive CRC and explore the treatment consequences associated with vertical margin status. METHODS: We analyzed 395 submucosally invasive CRC cases in 389 patients who underwent ER at our hospital between 2008 and 2020. The presence of residual tumors and simultaneous lymph node metastasis in patients who underwent additional surgery was assessed and compared between the vertical incomplete ER and the vertical margin-negative groups. RESULTS: Among the patients, 270 were men, with a median age of 69 years. The vertical incomplete ER rate was 21.5%, with positive vertical margins and unclear vertical margins identified in 12.2% and 9.3% of the cases, respectively. Among 154 patients who underwent additional surgery after ER, the vertical incomplete ER group had a significantly higher residual tumor rate than the vertical margin-negative group (P = 0.001). The vertical incomplete ER group had a significantly higher lymph node metastasis rate than the vertical margin-negative group (P = 0.029). CONCLUSION: This study clarified the substantial risk of vertical incomplete ER in submucosally invasive CRC and revealed the high risk of residual tumor and lymph node metastasis in vertical incomplete ER for submucosal CRC.
Colorectal Neoplasms , Male , Humans , Aged , Female , Lymphatic Metastasis , Retrospective Studies , Neoplasm, Residual/surgery , Risk Assessment , Colorectal Neoplasms/surgery , Colorectal Neoplasms/pathology , Risk Factors
Background and study aims Endoscopic treatment strategies for small superficial duodenal epithelial neoplasia (SDET) have not been established, and the R0 resection rates of all previously reported endoscopic techniques are somewhat low. Furthermore, no reports of cap-assisted endoscopic mucosal resection (EMRC), which is reportedly associated with a relatively high R0 resection rate, have been evaluated in sufficient numbers of patients. Therefore, we assessed the efficacy and safety of EMRC for SDETs ≤ 10 mm in a retrospective cohort study. Patients and methods We examined a prospectively maintained database and identified 248 consecutive patients (248 lesions) who had undergone endoscopic resection for SDETs ≤ 10 mm between January 2017 and June 2022. Our treatment strategy was consistent, with EMRC indicated for all SDETs ≤ 10 mm without non-lifting signs. The primary endpoint was the R0 resection rate. Results Overall, 20 lesions had non-lifting signs and were selected for endoscopic submucosal dissection, while the remaining 228 lesions were treated with EMRC. As a result of EMRC, the median tumor size was 5 mm, and the mean procedure time was 5 minutes. Most of the lesions (89.2%) were located in the descending part. The R0 resection rate was 97.4% (222/228 cases), and the en bloc resection rate was 99.6%. Only seven patients(3.1%) experienced adverse events (6 patients, delayed bleeding; 1 patient, acute pancreatitis), which were successfully managed without surgical intervention. Furthermore, no recurrences were observed. Conclusions We have demonstrated that EMRC is an effective and safe treatment for SDETs ≤ 10 mm that do not have non-lifting signs.
Video 1Presentation of a newly invented transparent silicon attachment, the static electricity fastening tape hood, and its creation process, durability, and usefulness for various endoscopic procedures.
Video 1Outline of how self-assembling peptide gel can be used ex vivo.
Background and study aims: Radial incision and cutting (RIC) is indicated for refractory benign esophageal strictures after curative treatment for esophageal cancer and has shown favorable short-term outcomes. However, re-stricture after RIC may occur in the long term, and RIC is performed repeatedly in such cases, but the efficacy and safety of repeated RIC are unclear. Therefore, we aimed to demonstrate the efficacy and safety of the repeated RIC for refractory benign esophageal strictures after surgical and non-surgical treatment. Patients and methods: Between April 2008 and September 2019, we enrolled patients who were treated with the first RIC for benign esophageal strictures. The RIC was indicated for the refractory stricture and repeatedly performed for re-refractory esophageal stricture after RIC. We retrospectively evaluated the 6-month refractory stricture-free rate, and adverse events (AEs) in the first RIC and repeated RICs. Results: Forty-six patients (39 men, 7 women; median age, 71 years, range 49-85) were included. RIC was performed once in 24 patients (non-repeated RIC group) and two or more times in 22 patients (repeated RIC group). In all patients, the 6-month refractory stricture-free rate after the first RIC were 42.3â%. In the repeated RIC group, the 6-month refractory stricture-free rate after the first and repeated RICs were 18.2â% vs 18.2â%, respectively. No AEs were noted. Conclusions: Repeated RIC could be effective in the short-term and safe even for patients with refractory benign esophageal stricture after the first RIC. However, it cannot be considered curative treatment for refractory stricture because of poor long-term results.
BACKGROUND: Perigastric abscess caused by delayed perforation after endoscopic submucosal dissection is a very rare complication. In principle, delayed perforation after endoscopic submucosal dissection is treated surgically. Herein, we report a case of perigastric abscess caused by delayed perforation after gastric endoscopic submucosal dissection that was treated conservatively, without perforation closure, and in which the patient was discharged from hospital in a short period. CASE PRESENTATION: A-74-year-old Asian man was diagnosed with having early gastric cancer on follow-up endoscopy and was admitted to our hospital for endoscopic resection. Endoscopic submucosal dissection was performed without intraoperative complications. On postoperative day 2, the patient complained of a slight abdominal pain localized to the epigastric region and a small amount of melena. A computed tomography scan revealed the presence of free air in the peritoneal cavity, and a little fluid collection abutting the dorsal area of the stomach. An endoscopy examination showed a deep ulcer with the accumulation of pus, suggesting a perforation in the post-endoscopic submucosal dissection ulcer. We diagnosed a perigastric abscess, caused by delayed perforation after endoscopic submucosal dissection, and opted for conservative treatment, leaving the perforation site open to allow spontaneous drainage from the abscess into the stomach. A follow-up computed tomography scan revealed an encapsuled and localized perigastric abscess on postoperative day 5, and the disappearance of the free air and the regression of the perigastric abscess on postoperative day 7. A follow-up endoscopy examination on postoperative day 7 showed the closure of the perforation. Finally, surgery was avoided, and the patient was discharged on postoperative day 14, after a relatively short hospital stay. CONCLUSION: Regarding the treatment of perigastric abscess, caused by delayed perforation after endoscopic submucosal dissection, leaving the perforation site open to allow spontaneous drainage may shorten the conservative treatment period.
Endoscopic Mucosal Resection , Stomach Neoplasms , Male , Humans , Abscess/etiology , Abscess/therapy , Endoscopic Mucosal Resection/adverse effects , Conservative Treatment , Ulcer , Stomach , Stomach Neoplasms/surgery , Endoscopy, Gastrointestinal , Treatment Outcome
While duodenal neoplasms of the gastric phenotype are uncommon and their natural history is unknown, gastric neoplasms of gastric phenotype reportedly grow rapidly and can invade the submucosa. Several studies suggest that duodenal neoplasms of gastric phenotype might have a high risk of deep invasion and lymph node metastasis. Duodenal neoplasms of gastric phenotype might also have a high biological malignancy and likely require early treatment if detected. Here, we report two cases of intramucosal duodenal carcinoma with a gastric phenotype that grew rapidly but was successfully resected endoscopically.
OBJECTIVES: Endoscopy poses a high risk of severe acute respiratory syndrome coronavirus 2 infection for medical personnel due to the dispersal of aerosols from the patient. We investigated the location and size of droplets generated during esophagogastroduodenoscopy (EGD) and endoscopic submucosal dissection (ESD), the contamination of the surrounding area before and after the procedures, and the effectiveness of using an extraoral suction device (Free arm arteo; TOKYO GIKEN, Inc., Tokyo, Japan). METHODS: Patients who consented to the study and underwent EGD or ESD between December 8, 2020, and April 15, 2021, at the National Cancer Center East Hospital were included. Adenosine triphosphate (ATP) hygiene monitoring tests and a particle counter were used for measurements. RESULTS: Assessments were performed on 22 EGD and 15 ESD cases. ATP hygiene monitoring tests showed significant elevations at three sites near the patient, and two sites 1.5 m away, for EGD, and at four sites near the patient and 1.5 m away for ESD. In both ESD and EGD, extraoral suction devices reduced the extent of the contamination. Particles <5 µm in size were generated during endoscopic procedures and dispersed from both the forceps hole and the patient's mouth. The extraoral suction device did not reduce the number of particles generated. CONCLUSIONS: During endoscopic procedures, cleaning the surrounding environment is important in addition to standard precautions the endoscopist and caregivers take. The use of extraoral suction devices can also potentially reduce contamination of the surrounding environment.
COVID-19 , Endoscopic Mucosal Resection , Humans , Prospective Studies , Suction , COVID-19/prevention & control , Respiratory Aerosols and Droplets , Endoscopy , Endoscopic Mucosal Resection/methods , Treatment Outcome
BACKGROUND: Gastric mixed neuroendocrine-non-neuroendocrine neoplasms are rare malignant tumors. The lack of specific findings makes it difficult to diagnose endoscopically. We report the case of early gastric mixed neuroendocrine-non-neuroendocrine neoplasms treated by endoscopic submucosal dissection. CASE PRESENTATION: An 81-year-old Japanese female underwent esophagogastroduodenoscopy for screening and was treated with endoscopic submucosal dissection for the diagnosis of early gastric cancer. Histopathologically, the lesion was diagnosed as mixed neuroendocrine-non-neuroendocrine neoplasms (tubular adenocarcinoma 2 60%, endocrine cell carcinoma 40%), pT1b(submucosa (SM) 900 µm), pUL(-), Ly(+), v(-), pHM0, pVM0. After additional surgical resection without adjuvant chemotherapy, she has had no recurrences or metastases for 3 years. CONCLUSIONS: Comparing narrow-band imaging magnified endoscopic findings with pathological findings, the depressed area with a lack of surface structure was consistent with the neuroendocrine cell carcinoma component, while narrow-band imaging magnification findings showed non-network vessels. In this case, we examined endoscopic findings of early stage mixed neuroendocrine-non-neuroendocrine neoplasms in detail and compared it with the pathological findings. We believe that these endoscopic findings contribute to the diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasms and can lead to its early detection.
Adenocarcinoma , Carcinoma, Neuroendocrine , Endoscopic Mucosal Resection , Neuroendocrine Cells , Neuroendocrine Tumors , Stomach Neoplasms , Female , Humans , Aged, 80 and over , Gastric Mucosa/pathology , Neuroendocrine Cells/pathology , Endoscopic Mucosal Resection/methods , Neuroendocrine Tumors/pathology , Stomach Neoplasms/pathology , Adenocarcinoma/pathology , Carcinoma, Neuroendocrine/pathology
BACKGROUND: Endoscopic submucosal dissection (ESD) is an optimal treatment for colorectal tumors; however, it is technically difficult, especially for non-experts. Therefore, a device that helps non-experts perform colorectal ESD would be beneficial. A double-balloon endolumenal interventional platform (DEIP) was recently developed to assist colorectal ESD through endoscope stabilization and traction. This study assessed the usefulness of colorectal ESD using the DEIP (DEIP-ESD) by endoscopists, including non-experts, in a living porcine model. METHODS: Two pigs were used to perform eight DEIP-ESD and eight conventional cap-assisted ESD (C-ESD) procedures. Three experts and five non-experts each resected one lesion using DEIP-ESD and one using C-ESD. We evaluated the treatment outcomes and performed stratified analyses between the experts and non-experts. RESULTS: Dissection speed was significantly faster in DEIP-ESD than in C-ESD (13.3 mm2/min vs 28.5 mm2/min, P = 0.002). However, the total procedure time did not differ significantly between DEIP-ESD and C-ESD. In the stratified analyses, the dissection speed of non-experts was significantly faster in DEIP-ESD than in C-ESD (10.9 mm2/min vs 25.1 mm2/min, P = 0.016), while that of experts increased in DEIP-ESD but to a lesser extent (19.1 mm2/min vs 28.8 mm2/min, P = 0.1). The total procedure time did not differ between DEIP-ESD and C-ESD for both experts and non-experts. The self-completion rate of non-experts also increased in DEIP-ESD. Moreover, the number of muscularis propria injuries induced by non-experts was fewer in DEIP-ESD than in C-ESD. CONCLUSIONS: DEIP could facilitate colorectal ESD by improving dissection efficiency without increasing adverse events, especially when performed by non-experts.
Colorectal Neoplasms , Endoscopic Mucosal Resection , Animals , Colorectal Neoplasms/pathology , Colorectal Neoplasms/surgery , Dissection/methods , Endoscopic Mucosal Resection/methods , Swine , Traction , Treatment Outcome
In the present study, we assessed the oral mucosal irritation potential of antimicrobial chemotherapy involving hydrogen peroxide (H2O2) photolysis with a 405-nm laser device at an output power of ≥100â¯mW in hamsters. Twenty-four cheek pouches from 12 male Syrian hamsters received 7-min treatment with pure water (PW), 3% H2O2, laser irradiation of PW at 100â¯mW, laser irradiation of 3% H2O2 at 100â¯mW, laser irradiation of PW at 200â¯mW, or laser irradiation of 3% H2O2 at 200â¯mW (nâ¯=â¯4 each). The diameter of the irradiation area was set at 3â¯mm; accordingly, the calculated irradiances (optical power densities) of the 100- and 200-mW laser lights were approximately 1400 and 2800â¯mW/cm2, respectively. In addition, 12 cheek pouches from six animals received laser irradiation of 3% H2O2 at 100â¯mW for 1, 3, or 5â¯min (nâ¯=â¯4 each). Each treatment was repeated three times at 1-h intervals. Macroscopic and histological changes were evaluated 24â¯h after the last treatment. In addition, in vitro bactericidal activity of the treatment against periodontal pathogens was evaluated. We found that 405-nm laser irradiation of 3% H2O2 caused moderate to severe oral mucosal irritation when performed at powers of 100 and 200â¯mW for ≥3â¯min, while the same treatment performed at 100â¯mW for 1â¯min resulted in mild irritation. Moreover, 1-min H2O2 photolysis at 100â¯mW caused aâ¯>4-log decrease in viable bacterial counts. These findings suggest that 1-min H2O2 photolysis, which can effectively kill periodontal pathogens, may be acceptable when a 405-nm laser device is used at 100â¯mW. However, use of the laser at a lower power would be preferable for the prevention of unnecessary oral mucosal irritation.
Anti-Infective Agents/pharmacology , Hydrogen Peroxide/pharmacology , Lasers , Mouth Mucosa/drug effects , Photolysis/drug effects , 3T3-L1 Cells , Animals , Anti-Infective Agents/chemistry , Anti-Infective Agents/therapeutic use , Cell Survival/drug effects , Cell Survival/radiation effects , Cricetinae , Electron Spin Resonance Spectroscopy , Male , Mice , Mouth Mucosa/metabolism , Mouth Mucosa/radiation effects , Periodontitis/drug therapy , Photolysis/radiation effects , Porphyromonas gingivalis/drug effects , Reactive Oxygen Species/chemistry , Reactive Oxygen Species/metabolism , Streptococcus mutans/drug effects
A case in which implantation of esophageal squamous cell carcinoma onto a post-dissection gastric ulcer was strongly suspected is presented. A 72-year-old man with alcoholic liver cirrhosis underwent esophagogastroduodenoscopy (EGD). Esophageal cancer (EC) (Mt, 20 mm, 0-Is) and gastric cancer (GC) (antrum, 15 mm, 0-IIc) were identified. Biopsy specimens revealed moderately differentiated squamous cell carcinoma (SCC) and differentiated adenocarcinoma, respectively. The GC was resected by endoscopic submucosal dissection (ESD) [14 mm × 9 mm, type 0-IIc, tub1, pT1a(M), ly0, v0, HM(-), VM(-)]. Two months after ESD, radiation therapy was started for the EC, and an almost complete response was obtained. Nine months after the ESD, a follow-up EGD showed a submucosal tumor-like lesion with ulceration, located immediately under the post-ESD scar, and biopsy specimens showed moderately differentiated SCC. There were no similar lesions suggesting hematogenous or lymphatic metastasis in the stomach.
Adenocarcinoma/surgery , Carcinoma, Squamous Cell/pathology , Endoscopic Mucosal Resection/adverse effects , Esophageal Neoplasms/pathology , Gastrectomy/adverse effects , Neoplasm Seeding , Stomach Neoplasms/surgery , Stomach Ulcer/pathology , Adenocarcinoma/pathology , Aged , Biopsy , Carcinoma, Squamous Cell/radiotherapy , Endoscopy, Digestive System , Endosonography , Esophageal Neoplasms/radiotherapy , Esophageal Squamous Cell Carcinoma , Gastrectomy/methods , Humans , Male , Stomach Neoplasms/pathology , Stomach Ulcer/etiology , Time Factors , Tomography, X-Ray Computed , Treatment Outcome
Induced pluripotent stem (iPS) cells have received remarkable attention as the cell sources for clinical applications of regenerative medicine including stem cell therapy. Additionally, labeling technology is in high demand for tracing transplanted cells used in stem cell therapy. In this study, we used quantum dots (QDs), which have distinct fluorescence abilities in comparison with traditional probes, as the labeling materials and investigated whether iPS cells could be labeled with QDs with no cytotoxicity. iPS cells could not be labeled with QDs alone but required the use of cell-penetrating peptides such as octaarginine (R8). No significant cytotoxicity to iPS cells was confirmed by up to 8 nM QDs, and the iPS cells labeled with QDs maintained their undifferentiated state and pluripotency. These data suggest that QDs can be used for fluorescence labeling of iPS cells.
